You can only navigate with the front buttons of your wii, or with a GameCube controller.
If you want to mod your Wii, use ModMii, it's an all in one solution. USB-loading is waaaaayyyy better then disc loading.
And why not ? It is an excellent guide ! Before ModMii's existence it was the ultimate guide to follow.
Sure ModMii makes everything a lot easier, I agree but that guide still is great IMHO.
Yes, I figured figured you did that :)
Download Winrar here http://www.rarlab.com/rar/wrar41b4.exe
Install it, and after that, rightclick the first rarfile and select extract.
It will extract the ISO file which you can burn with IMGBurn